Underwater floating devices are supposed to, simultaneously, float, be able to resist to high pressures due to the depth at which they are used and be able to resist mechanical loads.
Consequently, such devices must have an efficient density and an efficient mechanical structure in order to withstand pressure and mechanical loads during use.
The floating devices are also supposed to be watertight. In case of damage, they should not be filled entirely with water.
Techniques of seismic data acquisition usually require to tow streamers at depths comprised between 5 meters and 15 meters.
New techniques of seismic data acquisition require now to tow streamers at depths that can reach 80 to 120 meters. Thus, during operations, the floating devices are therefore supposed to resist to pressures possibly reaching 1.2 MPa, i.e. until 12 bars.
It is known to make a floating device with a foam core of PVC (Polyvinyl chloride) covered with a skin of polyurethane low pressure. The foam is machined, which is expensive. The skin is in a thermosetting material, which is not recyclable.
Another device of this type is disclosed in US 2010/037402, which device comprises a hollow skeleton and a seal. This device has the drawback of being hollow, so that in case of damage, it will get full of water, and would not thus be able to float anymore. Another drawback of this known device is that it comprises a lot of fiberglass which create deformations of the panels which makes it difficult to assemble.
Another known floating device comprises an epoxy resin foam and a skin made of an epoxy resin or a polyurethane. Such thermosetting device is not recyclable, is expensive and fragile in case of collision. Furthermore, the epoxy resin foam comprises open cells which fill up with water in case of damage of the device.
Another known device comprises a foam of polyurethane which forms a skin when in contact with water. Such device is not recyclable and is expensive.